1. Field of the Invention
This invention pertains to a flexible and deformable fluid cushion to alleviate discomfort to a user due to excessive force loading on the user's ischial spines. In particular, this invention relates to a resilient, flexible and deformable fluid cushion which allows the user to sit on a base surface for prolonged periods of time with a minimization of discomfort and a minimized possibility of forming decubitus ulcers. More in particular, this invention directs itself to a fluid tight deformable fluid cushion defined by a closed housing having an upper surface member and a lower surface member joined each to the other for the purpose of containing a fluid medium therein. Still further, this invention relates to a fluid tight deformable fluid cushion housing having an intermediate plastic membrane dividing the interior of the housing into a first chamber and a second chamber containing therein first and second fluid mediums. Additionally, this invention relates to a fluid cushion having a pair of independent and isolated fluid chambers containing fluids of differing viscosities which lower the discomfort level of the user during prolonged periods of sitting. Still further, this invention directs itself to a deformable fluid cushion having a pair of through passages aligned in the neighborhood of the ischial spines of a user. This invention directs itself to a deformable fluid cushion where a tubular mechanism having sidewalls defines the through passages aligned with the ischial spines of a user. Further, this invention relates to a tubular mechanism having the sidewalls of varying cross-sectional diameters as a function of the vertical distance between the upper and lower surface members forming the fluid tight closed housing. More in particular, this invention directs itself to a tubular mechanism defining the through passages aligned with the ischial spines of the user wherein the through passages have an apex diameter substantially at the midpoint between an undeformed distance between the upper and lower surface members of the fluid tight closed housing. More in particular, this invention relates to a housing having tubular mechanisms which are sealed to an intermediate membrane layer or member dividing the interior of the fluid cushion into two independent fluid containing chambers. Still further, this invention directs itself to a deformable and resilient fluid cushion containing two fluid mediums where there is provided a wave damping mechanism within one of the internal chambers defined by the upper and lower surface members and the intermediate membrane layer member.
2. Prior Art
Deformable fluid cushions are known in the art. However, fluid cushions having particularly contoured and sized openings for interface with the ischial spines of a person for relief of discomfort in those particular user areas is not known to the Applicant.
The best prior art known to Applicant includes U.S. Pat. Nos. 180,528; 187,397; 4,766,629; 1,830,570; 1,673,636; 2,625,209; and, United Kingdom Patent #19985. However, none of these references provide for the overall fluid tight closed housing having a lower surface and upper surface members sandwiching an intermediate membrane member defining a pair of chambers for containing liquids of differing viscosity as is herein described. Additionally, none of these references are believed to provide for tubular mechanisms having tubular sidewalls with varying cross-sectional diameters when taken with respect to a vertical direction as is necessary to the subject invention concept.